The annual BioASQ challenge provides datasets, evaluation infrastructure and sub-challenges intended to foster the development of Artificial Intelligence methods that will help biomedical experts extract relevant information from the evergrowing scientific literature and specialized databases. The BioASQ challenge started as a European research project (FP7 ICT, 2012-14) coordinated by the Institute of Informatics and Telecommunications of NCSR "Demokritos". AUEB participated in the research project and played a central role in the organization of the question answering sub-challenges. Since 2015, the BioASQ challenge continues with funding mostly from the US National Institutes of Health (NIH). This year, AUEB participated as a contestant, along with a total of 26 teams from 11 countries. The prize was awarded at the BioASQ workshop of the 2018 Conference on Empirical Methods in Natural Language Processing.